Process of electroplating non-conducting substances with copper



. No Drawing.

UMIKIGHI UNNO, 0F TOKYO, JAPAN.

To (ZZZ whom it may concern:

Be it known that I, UMIKIGHI UNNo, a subject of the Emperor of Japan, residing at No. 20, Nichome, Shin-ogawa-machi, Ushigome-ku, city of Tokyo, andEmpire of Japan, have invented certain new and useful Improvements in Processes of Electroplat--. ing Non-Conducting Substances with Gopper, of which the following is a specification.

My invention relates to an improved process of electrically depositing a metal such as copper on non-conducting substances, such as wood, porcelain, paper, cloth, plaster, and the like, and has for its objects to provide an economical method whereby such substances can be coated, in a relatively short space of time, with a metallic'skin adapted to stand considerable wear.

My said invention has articular reference to that class of met od wherein the article to be treated is first impregnated with afsubstance adapted to expel air and moisture, and is then coated with a conducting material. i

It has been proposed in. a process of'this nature to immerse the article in boiling white-wax, and it has also been proposed in another class of process to coat thearticle with a mixture containing gold graphite.

In carrying my invention into effect, the

" article to be coated is first treated so as to while the bath is kept hot until the article is thoroughly impregnated with the mixture, and provided with a wax coating. i

' It is then treated witlia' conducting mixture, made from {the following ingredients Graphite 100 parts Mercury 2 parts 'Auric chlorid 1 part Sulfuric ether 50 parts,

(said materials being mixed in the presence of a small amount of mineral acid, such as nitric and sulfuric).

The said mixture is dried and powdered,

I Specification of Letters Patent.

Patented Sept. 7, 1920.

Application filed November 21, 1917. Serial No. 203,179.

during which operation it is made homogeneous, and the ether, of course, evaporates. The dried mixture is then applied to the surface of the impregnated article, by means of a brush, or in any other convenient manner, to the wax-coated surface of the article in such manner that the whole of such surface is covered therewith. The auric chlorid being soluble in the sulfuric ether, is uniformly distributed in the mixture, and as both mercury and auric chlorid are better conductors than graphite, the article is thus easily provided with an equally distributed conductive coating in a finelydivided condition, whereby the time and cost of plating are considerably reduced.

n electrolytic bath of copper sulfate solution of ordinary strength is provided, in which the article to be coated is now immersed and attached to the negative pole, while the positive pole-is a plate or the like of copper.v An electric current, such as is usually emplo ed for electroplating, a1

- though prefera 1y of slightly, less voltage, is

passed through the bath, and according to the length of time during which the passage of the current is mainta ned, a copper coating of greater-p ssthickness .will be deposited onthe artic e" under treatment.

Having fullyjdescribed my invention, what I claim as"new,";and desire to secure by Letters Patent, is Y 1'. The method of electrolytically depositing metal upon 'an article made of a nonconducting substance which consists in impregnating the article with a mixture of beeswax, paraflin wax' and white wax, preparing a coating mixture by mixing together .relatively large proportions of graphite and sulfuric ether, and relatively small propor- 'tions of mercury and gold chlorid, drying and powdering the mixture, and coating the impregnated article therewith, then immersing the article so coated in a bath of electrolyte' and electrolytically depositing a metal on said article while so immersed.

2. The method of electrolytically depositing metal upon an article made of a nonconducting substance which consists in impregnating the article with a mixture of beeswax, paraffin wax, and whitewax, coating the impregnated article with a powder formed from a homogeneous mixture con:

taining a relatively large amount of graph- I ite, and relatively small amounts of merarticle While so immersed.

In testimony whereof I affix my signature in the presence of two Witnesses.

UMIKICHI UN N O.

Witnesses DAIJIRO IsHI, KoIoHI URIN. 

